润滑条件下Mg_2B_2O_5/6061Al基复合材料摩擦磨损性能研究

Friction and Wear Behaviors of Mg_2B_2O_5 Whisker Reinforced 6061Al Matrix Composites under Lubricated Condition

采用自制的机械-超声混合搅拌设备制备出Mg2B2O5/6061Al铝基复合材料,复合材料的体积分数为2%。研究了载荷和滑动速度对基体以及复合材料的摩擦磨损性能的影响。实验结果表明,基体和复合材料摩擦系数总体上随着载荷和滑动速度的增加而减小。基体和复合材料的磨损率随载荷和滑动速度的增加而明显的增大,且基体和复合材料均存在一个临界载荷和临界滑动速度。当载荷和滑动速度到达临界值后,磨损率均急剧增大,此时试样摩擦磨损机制由微观疲劳磨损和磨粒磨损向粘着磨损与剥离磨损转变。

The friction and wear properties of Mg2B205 whisker reinforced 6061A1 matrix composites fabricated by power ultrasonic-stir casting process were investigated using a ball-on-disk wear-testing machine against a GCr45 steel counterface under lubricated conditions. The volume fraction of the composites was 2%. The relationship between the wear rate and the coefficient of friction was discussed. Results indicate that： as the applied load and sliding speed steadily increased, the friction coefficients of the matrix alloy and the fabricated composites decrease and the wear rate increases. Both of the applied load and sliding velocity of the matrix and composite have a critical value, when the applied load and sliding velocity reach the critical values, the wear rate increased sharply and the wear mechanisms of the composites shifted fi＇om mild to severe regime.